Manufacture of pneumatic tires



Dec. 29, 1936.

L, HERBERT 'Er AL 2,065,97l

MANUFACTURE OF PNEUMATIC TIRES Filed Feb. 12',- 1935 2 Sheets-Sheet 1Dec. 29, 1936. l L HERBERT E1- AL. 2,065,971

MANUFACTURE OF PNEUMATIC TIRES Y Filed Feb. 12, 1935 2 Sheets-Sheet 2/f//IH Patented Dec. 294, 1936 f UNITED STATESv PATENT OFFICE rMANUFACTURE OF PNEUMATIC TIRES Leonhard Herbert, Frankfort-on-the-Main,and Adolf Frhlich, Hannover, Germany Application February 121935, SerialN0. 6,250

6 Claims.

This invention relates 4to a device for producing pneumatic tires,preferably for motor vehicles.

In the manufacture of cord tires, the frame was hitherto built; up on around core, a flat drum, a shouldered drum or on a core curved to suitrequirements. When a round core was used, the cord was applied to thecore as an endless band and in a single or double layer with a certainWhen, under such old methods, a tire has been` worked and finished tothe extent mentioned, the heating coil or tube was inserted therein andnecessarily subjected to severe lstrain by bending and pulling.

Tl'iese manufacturing methods `are open to the objection that the threadspacings and the tensioning in the cord layers become uneven duringworking whereby the carrying capacity of the structure is decreased.

The present invention eliminates these drawbacks by providing a methodand device for combining the hitherto separated mechanical and manualoperations into one mechanical process and thus reducing unreliabilitydue to hand work to a minimum.

Compared with heretofore existing methods and devices, the purelymechanical process of building up the tire from the layers of cordaffords the advantage that the layers do not flap while they are placedaround the core and the structure of the cord fabric is thus notdistorted or displaced. Furthermore, the tire is built directly upon theheating tube which is subsequently inserted. and during insertionsubjected to sharp bending and pulling, so that, by the presentarrangement, the life thereof will be increased.

In the machine according to the invention for carrying out the newprocess two axially displaceable drums of equal size are/provided, oneat each side of the core which is also the vulcanizing element, on whichthe layers of cord are arranged in known manner. The'two drums are thenwithdrawn towards the sides and the endless cord band is simultaneouslygripped at both edges by tongs .disposed at the adjacent edges of thedrums, each of the tongs being carried and operated by a lever system.The equidistantly gripped cord band is then placed by one movement at acertain tension around the round core serving also as a vulcanizing unitby means of the guide curves of a slotted annular basketlike lever guide'cooperating with the lever systems.

` By way of example, one form of a device according to the invention isillustrated in the accompanying drawings, in which Figure 1 is a'longitudinal section of the device with the basketlike tongs guide inelevation; Fig'. 2 is a longi tudinal section partly in elevation ofthebasketlike guide on a larger scale showing the slotted and rotatablydisposed guide ring for the lever arms; Fig. 3 is a. side view of Fig. 2seen from the left; Figs. 4, 5, and 6 are detail views of the three mainworking positions of the gripper tongs for engaging the edges of thecord band; and the line- M-M in Fig. 1 indicates the center of themachine of which the left side is drawn only, the right-hand side beingindicated in spots by broken lines.

Referring to the drawings, layers of cord are arranged upon drums2, 2which are symmetrically disposed on opposite sides of the core 5 toproduce the endless cord band I. The drums 2, 2 are secured to gearwheels 3 by means of the guide rods 4 and, togethefwith the bearing 3aand the shaft 3b, are movable in the direction of the arrows A from thecenter of the machine into the position shown in Fig. l, so that theendlessly formed cord band I may fall with its edges I/a, I a into theopen tongs 'I uniformly arranged at the inner edges of the drums 2, 2and is equidistantly gripped by the tongs 7.

Each pair of tongs l is carried by a lever 8 which is articulated at 9to a guide rod I 2 screwed at I0 to the gear body I I, while the guidering I3,

under the action of the spring I2a, rests against .longitudinallyimmovable slotted guide basket I4 for the tongs, in which thecorrespondingly slotted guide ring I5 for the lever arms.- I 6, Figs.

1 and 4-6, of the tongs 1 is rotatably arranged. By means of the discI6a the ring I5 is rotatably arranged in the guide basket I4 so thatthek disc I6a engages behind the inner projection I8 and is supported bythe flange I'I of the hub of the basket I4. In the guide ring I5 aslotted boss I5a is inserted to serve as additional guide and stop forthe lever arms I6.

The jaws of the tongs 1 have their fulcrum at 8a on the levers 8. Thefree ends of .the jaws each carry one of the gripper rings I9 and 20,preferably made of rubber;y which hold the band I firmly in the tongsand urge the tongs toclosed position. The elastic rings I9, 20 tendconstantly to draw the tongs 1 and the edges of the band I towards thecenter of the machine and around the core 5 and thus, according to theinvention, re-

to draw the band I about the core 5.

The tongs move as follows:

The outer ring I9 and the inner ring 20, which embrace `the faces of thetongs 1 which are disposed in a circle around the guide head I4, urgethe tongs to closed position and t draw them between the bars I4a of theguide member I4, which are curved corresponding to the profile of thecore '5. The band I is positively guided and controlled by the leverarms I6 of the tongs 1, which swing between the bars I4a in the slots ofthe guide I4 and determine the opening and closing of the tongs. Whenthe guide ring I5 is turned relative to the guide I4 by means of thesegment 22 positioned in the bearings 2|, 2I and acts on the bossmemberI1, the lever arms I5 cannot enter the slots I5b of the guide'ring I5and boss I5a but must'rest on the ribs I5c against the tensioning effectof the rubber ring I9 and keep the tongs open to receive the work, asindicated in Fig. 4.

The toothed segment 22 is in mesh with the segment 22a and itsoscillatory motion for adjusting the members I5a, I5b relative to theguide head I4 is controlled by -the stop lever 23 which strikes the cams25, 25 on the spindle 24 which during operation is reciprocated with themembers 2, 3, 3a, 3b, and II in the direction of the longitudinal axisof the machine relative to the core 5, whereas the members I4, I5 withtheir respective parts are not displaced on the shaft. a

In the position shown in Fig. 'i the lever arms I6 are supported by theribs I5c and the sides of the tongs 1 press against the edge of the drum2. The rubber band 20 acts against the lever arms I6 so as to cause thetongs to be open for the reception of the work. If the guide ring I5 isadjusted by means of the segment 22 andthe cams 25 relative to thepositions oi' the guide head I4, the lever arms I6, under the action ofthe rubber member 20, will quickly move between the ribs I 5b and thetongs will grip the work and close up instantly while, simultaneously,the

lever systems are di'splacd towards the core 5,

as indicated in Fig. 5. The ringsI9 and 20 then cause the tongs 1holding the edges of the cord band I to slide down on the curves I4b ofthe bars I4a while the lever systems are moved farther towards the core5 until the end position 'accordins to Fig. 6 has been reached. The cord.core 5 to press with the aid of the closed rings I9, 20 the tire flangeagainst the'core.

We claim: l 1. In a device for the purpose set forth, a core,

a pair of drums movable into and out of juxta-1 position to the sides ofsaid core and adapted to have a cord fabric disposed thereon, pairs ofgripping jaws disposed inspaced relation about each drum, and means toactuate said jaws to grip on the edges of the cord fabric and draw thefabric'into close relation to the core.

2. In a device for the purpose set forth, a core, a pair of drumsmovable into and out of juxtaposition to the sides of said core andadapted to have a cord fabric disposed thereon, pairs of gripping jawsdisposed in spaced relation about each drum, means, to actuate said jawsto grip on the edges of the cord fabric and draw the fabric into closerelation to the core, and means constantly urging said pairsof jaws toclosed positions. f

3. In a devicefor the purpose set forth, a core, a pair of drums movableinto and out of juxtaposition to the sides of said core and adapted tohave a cord fabric disposed thereon, pairs of gripping jaws disposed inspaced relation about each drum, means to actuate said jaws to grip onthe edges of the cord fabric and draw the have a cord fabric disposedthereon, pairs of gripping jaws Idisposed in spaced relation about eachdrum, means to actuate said jaws to grip on the edges of the cord fabricand draw the fabric into close relation to the core, means constantlyurging said pairs of jaws to closed positions, and means to guide saidjaws along radial pathshaving a common center.

5. In a device `for the purpose set forth, a core, a pair of drumsmovable into and out of juxtaposition to the sidesof saidcore andadapted to have a cord fabric disposed thereon', pairs of gripping jawsdisposed in spaced'relation about each drum, 'means to actuate said jawsto grip on the edges of the cord fabric and draw the fabric into closerelation to the core, means constantly urging said pairs of jaws toclosed positions, and other means adjustable to hold said jaws in openedpositions.

6. In a device for the purpose set forth, a core,

